Goofy invents a tank that will go underwater and fly. On a test run they find a huge air-filled undersea cavern with fields and a city. Their tank is stolen by Count Drakova, who somehow manages to render it invisible. Mickey and Goofy recover the tank and go to the city where they find that Count Drakova is threatening to make a man disappear if the King does not deliver a chest of gold to him.; Pluto gets an inferiority complex after seeing the large and vicious animals in the zoo.; Mickey has trouble getting a carton of eggs from the store to his house without dropping them.; Mickey gets a new wire sound recorder, but Morty and Ferdie knock it over while playing with Pluto and he has to repair it.; Mickey and Goofy are told to paint a house red and white. Mickey paints his side white with red shutters, while Goofy paints his side red with white shutters.